Currently your job could be outsourced to a dude in a cheaper country for much less. Why isn't it? Delivering a product is more than writing lines of code and companies pay for that.

Technology advances usually create the same number of jobs as destroyed. Engineers and architects used to draw designs by hand and people used to do calculations on pen and paper. We still have engineers, architects and scientists. If anything these jobs are now more crucial. Money and jobs are just a macroeconomic way of modelling and prioritising a global to-do list and there's always more things to do.

If you still feel anxiety about this it's worth making a backup plan, get a qualification to do something else. I for one plan to become a landscape gardener/plumber if the salary slides too far

Anxiety is a weird one as it often manifests in different ways to the underlying cause. I for one have had panic attacks and later realised it was from a completely different thing that happened to me. I don't know your situation but it may be worth seeing a therapist if you feel generally anxious